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windjammer
09-15-2005, 10:51
I have an 02 2500HD with a brake problem. When I am coming to a stop, I will feather the brakes to slow next a push with more pressure and come to a stop. But then I then feel a quick release/grab where the truck does move forward before stopping. If I do a quick stop, there is no release/grab slippage. Any ideas a to what is allowing the release/grab to happen?
thanks,
windjammer
02 2500HD

windjammer
09-16-2005, 07:19
Has no one else has experienced this problem before?
windjammer

DmaxMaverick
09-16-2005, 07:38
The 2001+ HD brake systems have been, generally, extremely reliable and effective. Very few complaints have been made in regards to them, and in most cases, problems were not brake related.

A couple things to check:

Wheel seals. If you have a leaky seal, lube can wet the pads, causing abnormal braking.

Output spline. (tranny/transfer case to driveshaft yoke)
A "dry" spline can grab/release, causing a perceived braking and/or a tranny shift issue.

Tranny downshift, just before the stop. The Allison tranny can drop hard to 1st gear in some conditions, causing a "lurch" feeling. If your '02 hasn't had TCM updates since new, it is likely going to do this on ocasion.

The nature of "drive by wire" can also cause "abnormal" issues. The engine will attempt to hold a minimum RPM, and if it forecasts a load, it will ramp the RPM's. You've probably noticed this while maneuvering into/out of parking stalls.

The hydroboost system also has an effect on engine load, brake pedal feel, and braking pressure. Engine RPM changes can/will change the feel and effectiveness of braking. Adding steering input while braking can also effect this.

Generally, when you post an issue and don't get a response, it means there are a bunch of readers staring at their monitors, scratching their heads. Be patient. Someone will relate to your issue. Sometimes, it takes a while for that member to speak up.

I'm moving this topic to the Drivetrain forum. Good luck!